It is remarkable that in the _succulent fruits_, such as the strawberry, the raspberry, currant, apple, orange, melon, &c., and which, from their very nature, are likely to attract animals to use them, and in eating which _the seeds are likely to be swallowed_, they are fortified by a doubly-protective coating; the pips of the apple, orange, &c., and the seeds of the strawberry and raspberry, pass through the digestive organs, not only unharmed, but their germinating powers are even improved by the warmth and trituration of the stomach. Indeed, the stomachs of quadrupeds and birds have been made the vehicles of propagating plants, and distributing them to the widest geographical latitudes. It is even said of some seeds that they will not germinate until they have passed through the digestive organs of an animal. [Verse: "And it was commanded them that they should not hurt the grass of the earth, neither any green thing, neither any tree."--REVELATION IX.] 1287. _Why do animals that graze, crop the tender blades of grass, but avoid the tall stems?_ Because they are tempted by the greater sweetness and tenderness of the young blades; and in this temptation a very important end is served; for, by avoiding the stems that have grown up, _the animals spare the matured plant by which seeds are borne_, and by which the supply of food is to be continued. 1288. _Why do the eggs of butterflies lie dormant during the winter?_ Because the _coldness of the winter_ would be fatal to the life of the young insects; and the absence of vegetation would leave the caterpillars to _perish of starvation_, if they were developed during the winter months. [Illustration: Fig. 76.--CATERPILLAR FEEDING.] 1289. _Why do caterpillars appear in the spring?_ Because the increasing warmth of the sun developes the living embryo, _at the same time that it developes the vegetable germ_. The warmth, therefore, that calls the caterpillar from its embryo sleep, also kindles the germinating power of the vegetable upon which it is destined to feed. The worm awakes and finds the bountiful table of nature spread for it. [Verse: "Thou shalt plant vineyards, and dress them, but shalt neither drink of the wine, nor gather the grapes: for the worms shall eat them."--DEUTERONOMY XXVIII.] 1290. _Why does the caterpillar eat voraciously?_ Because it _grows rapidly_, and a large amount of vegetable matter is necessary to supply the rapid growth of its animal substance. Caterpillars in the course of a month devour 60,000 times their own weight of aliment. [Illustration: Fig. 77.--THE UNDER SIDE OF THE CHRYSALIS OF THE PEACOCK BUTTERFLY.] [Illustration: Fig. 78.--THE SAME CHRYSALIS, WITH PART OF ITS SHEATH RAISED TO SHOW THE PARTIALLY-FORMED WINGS, &c.] 1291. _Why do caterpillars pass into the state of the chrysalis?_